32. Solanum nigrum Linnaeus, Sp. Pl. 1: 186. 1753.
[I W]
Black nightshade, morelle noire
Solanum nigrum subsp. schultesii (Opiz) Wessely
Herbs, annual or perennial, erect or sprawling, unarmed, to 1 m, glabrescent to moderately pubescent, hairs unbranched, to 1 mm, usually eglandular or occasionally glandular. Leaves petiolate; petiole 0.5–3 cm; blade simple, ovate, 3.5–7 × 2.2–5 cm, margins entire to coarsely toothed with 3–5 lobes per side, base truncate to cuneate. Inflorescences extra-axillary, unbranched or occasionally forked, racemelike, (3–)4–10-flowered, 1–2 cm. Pedicels 0.5–1 cm, spreading to occasionally recurved in flower and fruit. Flowers radially symmetric; calyx not accrescent, unarmed, 1.5–2 mm, sparsely pubescent, lobes deltate, spreading to reflexed in fruit; corolla white with yellowish central star, stellate, 1–1.5 cm diam., without interpetalar tissue; stamens equal; anthers ellipsoidal, (1.8–)2–2.5 mm, dehiscent by terminal pores that open into longitudinal slits; ovary glabrous. Berries dull or slightly shiny purple-black or green to yellowish green, globose, 0.5–1 cm diam., glabrous, without sclerotic granules. Seeds yellow, flattened, 1.8–2 × 1.5–1.6 mm, minutely pitted. 2n = 72.
Flowering May–Oct. Disturbed areas, irrigated fields; 0–2200 m; introduced; B.C., N.S., Ont.; Alaska, Calif., D.C., Fla., Ga., Idaho, Iowa, Maine, Md., Mass., Mo., Mont., Nev., N.J., N.Y., N.C., Okla., Oreg., Pa., Tex., Utah, Va., Wash.; Eurasia, n Africa; introduced also in Pacific Islands (New Zealand), Australia.
Many regional floras have used Solanum nigrum as the name for various species in the black nightshade group, and it can be difficult to distinguish this species from S. emulans and S. nigrescens. Solanum nigrum can be distinguished from the native North American species of the black nightshade group (S. americanum, S. douglasii, S. emulans, S. interius, S. nigrescens) by its thicker peduncles and pedicels, larger seeds, and fruits lacking sclerotic granules. Solanum nigrum was probably introduced from northern Europe and has been locally naturalized in North America.
